Henry Brewster Cook was born on November 1, 1843, in Bristol, Connecticut, to Havilla and Sophia Cook. His father was a shoemaker who owned $1,000 of real estate by 1860. He grew up and attended school in Bristol. At the age of 16, he left school and began working at a clock factory.
He enlisted in the Union army on July 29, 1862, and he mustered in as a private in Company K of the 16th Connecticut Infantry on August 24. The regiment took part in the Battle of Antietam, the Battle of Fredericksburg, and the siege of Suffolk. He was promoted to corporal on February 24, 1864. Confederate forces captured him at Plymouth, North Carolina, on April 20, 1864, and he was paroled on December 10, 1864. He mustered out on June 24, 1865.
Cook returned to Bristol after the war and resumed his work as a clockmaker. He soon began working in his father’s shoe store, and when his father died in 1869, he took over the business. By 1870, he owned $3,500 of personal property.
He married Caroline O. Birge, but she died in 1873 shortly after giving birth. Their daughter Lotta died a year later. He then married Alice K. Robinson around 1876, and they had at least two children: Harry, born around 1879; and Daisy, born around 1889. They lived in Bristol, and Cook continued to operate the family shoe store. He applied for a federal pension in February 1901 and eventually received one. By the early 1900s, Cook was reportedly “one of the leading residents of Bristol.” He died on May 15, 1911, “after an illness of several weeks.”